Aim: The Crimean-Congo hemorrhagic fever virus(CCHFV) is classified within the Nairovirus genus in the Bunyaviridae family. Mean platelet volume (MPV) is a biomarker of platelet function and activity. Platelet activity and aggregation capacity can be determined by measuring mean platelet volume (MPV). MPV is a parameter that has been associated with the diseases in many publications. The aim of this study is to investigate the change in the MPV values in patients with CCHF. Material and Method: The study was designed in the Artvin State Hospital. We recruited 74 patients with CCHF Thirty healthy individuals were included as a control group whom were age and gender matched with CCHF patients. We compared the levels of MPV, platelet counts, age, gender, hemoglobin, white blood cell between CCHF patients with (and) healthy individuals. Data were analyzed using the Statistical Package for the Social Sciences (SPSS Inc., Chicago, IL, USA) version 15. The t-test or Mann-Whitney U test was used. Level of statistical significance was considered p < 0.05 and the results were presented as mean +/- standard deviation. Results: There was no significant difference between the patients and controls in terms of age and gender. The mean platelet volume was 8.98 +/- 1.13 in CCHF group and 8.15 +/- 0.53 in the control group. There was a statiscically significant difference between the groups(p<0.001). Platelet counts and leucocyte were significantly lower in the CCHF group. Five patients died, thus the fatality rate was 6.8 %. Discussion: In conclusion, the present study demonstrated that MPV is increased in CCHF. MPV may be a low-cost indicator for CCHF when together with other parameters. We think that further studies with higher number of patients are required in the future.